Progressive insolubilization

Acidic hydrolysis of the amide group at pH 4.5 is a very slow reaction. Strong acidic conditions leads to a progressive insolubilization of the reaction product because of formation of cyclic imide structures ... 

These results led to the conclusion that denaturation and/or insolubilization of actomyosin and myosin during frozen storage is a result of aggregation caused by the progressive increase in intermolecular crosslinkages due to formation of hydrogen bonds, ionic bonds, hydrophobic bonds and disulfide bonds. 

In view of the progress in the field of immobilized or insolublized enzymes, definition of the terms employed is required. The term immobilized applies to enzymes etc. which have been reacted with another molecule to give a product of greater molecular size, i.e. the mobility of the enzyme, etc. in solution has been reduced. However, such derivatives may be water soluble or insoluble. By international agreement the use of the term immobilized is recommended rather than use of the original term insolubilized which does not encompass the water-soluble macromolecular derivatives. 

In the polyacrylamide dispersion polymerization process, multivalent salts are used for the purpose of insolubilizing and depositing the polymer and are formulated to produce a poor solvent for the particular polyacrylamide being synthesized. At the onset of polymerization reaction, the formed polymer is soluble in the polymerization medium. As the reaction progresses, the polymer phase separates forming particles (0.1-10 pm) that are kept from agglomeration by the use of polymeric stabilizers. A mechanistic hypothesis of the formation of polyacrylamide dispersions was reported by Selvarajan [43]. 

---